The objective of this training grant is to teach Postdoctoral Fellows to perform independent research in the area of Radiation Biology, so that they may make significant contributions to the fields of Radiation Oncology and Cancer Biology. This goal will be accomplished using a multi-faceted approach consisting of 1) providing training in the laboratories of outstanding scientists at Vanderbilt University School of Medicine who utilize cutting edge techniques coupled with highly collaborative approaches, 2) course work in the areas of Radiation Biology, Radiation Physics, and Cancer Biology, 3) multi-disciplinary Cancer Center Seminar Series designed to foster interactions between basic scientists and clinician/scientists who perform translational research, and 4) multi-disciplinary departmental seminar series. In addition, trainees will be exposed to clinical oncology environments at Vanderbilt. This program currently supports 3 Postdoctoral trainees, recruiting both M.D.s and Ph.Ds., the majority of which joined our program within 12 months of obtaining their degree. We wish to maintain this level of support. The program is currently funded to support a trainee for up to 3 years, allowing trainees not be well versed in Radiation Biology to become proficient. Training grant preceptors are well qualified to prepare individuals to become outstanding scientists in the field of cancer research, with a focus on radiation biology. They are extremely productive and are outstanding leaders in their respective fields. They are a mix of clinicians/scientists and basic scientists who have joint appointments in clinical and basic science departments at Vanderbilt University and the Vanderbilt-lngram Cancer Center. These preceptors will provide a multi-disciplinary, broad based approach for developing novel paradigms for cancer research. The American Cancer Society estimates that over 700,000 men and 650,000 women will develop cancer in 2005. Approximately 67% of these patients will be treated with ionizing radiation in an attempt to prevent the estimated 500,000 deaths that will occur this year. The purpose of our training program is provide sufficient numbers of highly trained clinicians and scientists who can impact the therapeutic effectiveness of radiation therapy.